<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<!-- NewPage -->
<html lang="en">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>FirstOrderConverter (Apache Commons Math 3.6.1 API)</title>
<link rel="stylesheet" type="text/css" href="../../../../../stylesheet.css" title="Style">
</head>
<body>
<script type="text/javascript"><!--
    if (location.href.indexOf('is-external=true') == -1) {
        parent.document.title="FirstOrderConverter (Apache Commons Math 3.6.1 API)";
    }
//-->
</script>
<noscript>
<div>JavaScript is disabled on your browser.</div>
</noscript>
<!-- ========= START OF TOP NAVBAR ======= -->
<div class="topNav"><a name="navbar_top">
<!--   -->
</a><a href="#skip-navbar_top" title="Skip navigation links"></a><a name="navbar_top_firstrow">
<!--   -->
</a>
<ul class="navList" title="Navigation">
<li><a href="../../../../../overview-summary.html">Overview</a></li>
<li><a href="package-summary.html">Package</a></li>
<li class="navBarCell1Rev">Class</li>
<li><a href="class-use/FirstOrderConverter.html">Use</a></li>
<li><a href="package-tree.html">Tree</a></li>
<li><a href="../../../../../deprecated-list.html">Deprecated</a></li>
<li><a href="../../../../../index-all.html">Index</a></li>
<li><a href="../../../../../help-doc.html">Help</a></li>
</ul>
<div class="aboutLanguage"><em><script type="text/javascript" src="http://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS-MML_HTMLorMML"></script></em></div>
</div>
<div class="subNav">
<ul class="navList">
<li><a href="../../../../../org/apache/commons/math3/ode/FieldSecondaryEquations.html" title="interface in org.apache.commons.math3.ode"><span class="strong">Prev Class</span></a></li>
<li><a href="../../../../../org/apache/commons/math3/ode/FirstOrderDifferentialEquations.html" title="interface in org.apache.commons.math3.ode"><span class="strong">Next Class</span></a></li>
</ul>
<ul class="navList">
<li><a href="../../../../../index.html?org/apache/commons/math3/ode/FirstOrderConverter.html" target="_top">Frames</a></li>
<li><a href="FirstOrderConverter.html" target="_top">No Frames</a></li>
</ul>
<ul class="navList" id="allclasses_navbar_top">
<li><a href="../../../../../allclasses-noframe.html">All Classes</a></li>
</ul>
<div>
<script type="text/javascript"><!--
  allClassesLink = document.getElementById("allclasses_navbar_top");
  if(window==top) {
    allClassesLink.style.display = "block";
  }
  else {
    allClassesLink.style.display = "none";
  }
  //-->
</script>
</div>
<div>
<ul class="subNavList">
<li>Summary:&nbsp;</li>
<li>Nested&nbsp;|&nbsp;</li>
<li>Field&nbsp;|&nbsp;</li>
<li><a href="#constructor_summary">Constr</a>&nbsp;|&nbsp;</li>
<li><a href="#method_summary">Method</a></li>
</ul>
<ul class="subNavList">
<li>Detail:&nbsp;</li>
<li>Field&nbsp;|&nbsp;</li>
<li><a href="#constructor_detail">Constr</a>&nbsp;|&nbsp;</li>
<li><a href="#method_detail">Method</a></li>
</ul>
</div>
<a name="skip-navbar_top">
<!--   -->
</a></div>
<!-- ========= END OF TOP NAVBAR ========= -->
<!-- ======== START OF CLASS DATA ======== -->
<div class="header">
<div class="subTitle">org.apache.commons.math3.ode</div>
<h2 title="Class FirstOrderConverter" class="title">Class FirstOrderConverter</h2>
</div>
<div class="contentContainer">
<ul class="inheritance">
<li><a href="http://docs.oracle.com/javase/7/docs/api/java/lang/Object.html?is-external=true" title="class or interface in java.lang">java.lang.Object</a></li>
<li>
<ul class="inheritance">
<li>org.apache.commons.math3.ode.FirstOrderConverter</li>
</ul>
</li>
</ul>
<div class="description">
<ul class="blockList">
<li class="blockList">
<dl>
<dt>All Implemented Interfaces:</dt>
<dd><a href="../../../../../org/apache/commons/math3/ode/FirstOrderDifferentialEquations.html" title="interface in org.apache.commons.math3.ode">FirstOrderDifferentialEquations</a></dd>
</dl>
<hr>
<br>
<pre>public class <span class="strong">FirstOrderConverter</span>
extends <a href="http://docs.oracle.com/javase/7/docs/api/java/lang/Object.html?is-external=true" title="class or interface in java.lang">Object</a>
implements <a href="../../../../../org/apache/commons/math3/ode/FirstOrderDifferentialEquations.html" title="interface in org.apache.commons.math3.ode">FirstOrderDifferentialEquations</a></pre>
<div class="block">This class converts second order differential equations to first
 order ones.

 <p>This class is a wrapper around a <a href="../../../../../org/apache/commons/math3/ode/SecondOrderDifferentialEquations.html" title="interface in org.apache.commons.math3.ode"><code>SecondOrderDifferentialEquations</code></a> which allow to use a <a href="../../../../../org/apache/commons/math3/ode/FirstOrderIntegrator.html" title="interface in org.apache.commons.math3.ode"><code>FirstOrderIntegrator</code></a> to integrate it.</p>

 <p>The transformation is done by changing the n dimension state
 vector to a 2n dimension vector, where the first n components are
 the initial state variables and the n last components are their
 first time derivative. The first time derivative of this state
 vector then really contains both the first and second time
 derivative of the initial state vector, which can be handled by the
 underlying second order equations set.</p>

 <p>One should be aware that the data is duplicated during the
 transformation process and that for each call to <a href="../../../../../org/apache/commons/math3/ode/FirstOrderConverter.html#computeDerivatives(double,%20double[],%20double[])"><code>computeDerivatives</code></a>, this wrapper does copy 4n
 scalars : 2n before the call to <a href="../../../../../org/apache/commons/math3/ode/SecondOrderDifferentialEquations.html#computeSecondDerivatives(double,%20double[],%20double[],%20double[])"><code>computeSecondDerivatives</code></a> in order to dispatch the y state vector
 into z and zDot, and 2n after the call to gather zDot and zDDot
 into yDot. Since the underlying problem by itself perhaps also
 needs to copy data and dispatch the arrays into domain objects,
 this has an impact on both memory and CPU usage. The only way to
 avoid this duplication is to perform the transformation at the
 problem level, i.e. to implement the problem as a first order one
 and then avoid using this class.</p></div>
<dl><dt><span class="strong">Since:</span></dt>
  <dd>1.2</dd>
<dt><span class="strong">See Also:</span></dt><dd><a href="../../../../../org/apache/commons/math3/ode/FirstOrderIntegrator.html" title="interface in org.apache.commons.math3.ode"><code>FirstOrderIntegrator</code></a>, 
<a href="../../../../../org/apache/commons/math3/ode/FirstOrderDifferentialEquations.html" title="interface in org.apache.commons.math3.ode"><code>FirstOrderDifferentialEquations</code></a>, 
<a href="../../../../../org/apache/commons/math3/ode/SecondOrderDifferentialEquations.html" title="interface in org.apache.commons.math3.ode"><code>SecondOrderDifferentialEquations</code></a></dd></dl>
</li>
</ul>
</div>
<div class="summary">
<ul class="blockList">
<li class="blockList">
<!-- ======== CONSTRUCTOR SUMMARY ======== -->
<ul class="blockList">
<li class="blockList"><a name="constructor_summary">
<!--   -->
</a>
<h3>Constructor Summary</h3>
<table class="overviewSummary" border="0" cellpadding="3" cellspacing="0" summary="Constructor Summary table, listing constructors, and an explanation">
<caption><span>Constructors</span><span class="tabEnd">&nbsp;</span></caption>
<tr>
<th class="colOne" scope="col">Constructor and Description</th>
</tr>
<tr class="altColor">
<td class="colOne"><code><strong><a href="../../../../../org/apache/commons/math3/ode/FirstOrderConverter.html#FirstOrderConverter(org.apache.commons.math3.ode.SecondOrderDifferentialEquations)">FirstOrderConverter</a></strong>(<a href="../../../../../org/apache/commons/math3/ode/SecondOrderDifferentialEquations.html" title="interface in org.apache.commons.math3.ode">SecondOrderDifferentialEquations</a>&nbsp;equations)</code>
<div class="block">Simple constructor.</div>
</td>
</tr>
</table>
</li>
</ul>
<!-- ========== METHOD SUMMARY =========== -->
<ul class="blockList">
<li class="blockList"><a name="method_summary">
<!--   -->
</a>
<h3>Method Summary</h3>
<table class="overviewSummary" border="0" cellpadding="3" cellspacing="0" summary="Method Summary table, listing methods, and an explanation">
<caption><span>Methods</span><span class="tabEnd">&nbsp;</span></caption>
<tr>
<th class="colFirst" scope="col">Modifier and Type</th>
<th class="colLast" scope="col">Method and Description</th>
</tr>
<tr class="altColor">
<td class="colFirst"><code>void</code></td>
<td class="colLast"><code><strong><a href="../../../../../org/apache/commons/math3/ode/FirstOrderConverter.html#computeDerivatives(double,%20double[],%20double[])">computeDerivatives</a></strong>(double&nbsp;t,
                  double[]&nbsp;y,
                  double[]&nbsp;yDot)</code>
<div class="block">Get the current time derivative of the state vector.</div>
</td>
</tr>
<tr class="rowColor">
<td class="colFirst"><code>int</code></td>
<td class="colLast"><code><strong><a href="../../../../../org/apache/commons/math3/ode/FirstOrderConverter.html#getDimension()">getDimension</a></strong>()</code>
<div class="block">Get the dimension of the problem.</div>
</td>
</tr>
</table>
<ul class="blockList">
<li class="blockList"><a name="methods_inherited_from_class_java.lang.Object">
<!--   -->
</a>
<h3>Methods inherited from class&nbsp;java.lang.<a href="http://docs.oracle.com/javase/7/docs/api/java/lang/Object.html?is-external=true" title="class or interface in java.lang">Object</a></h3>
<code><a href="http://docs.oracle.com/javase/7/docs/api/java/lang/Object.html?is-external=true#clone()" title="class or interface in java.lang">clone</a>, <a href="http://docs.oracle.com/javase/7/docs/api/java/lang/Object.html?is-external=true#equals(java.lang.Object)" title="class or interface in java.lang">equals</a>, <a href="http://docs.oracle.com/javase/7/docs/api/java/lang/Object.html?is-external=true#finalize()" title="class or interface in java.lang">finalize</a>, <a href="http://docs.oracle.com/javase/7/docs/api/java/lang/Object.html?is-external=true#getClass()" title="class or interface in java.lang">getClass</a>, <a href="http://docs.oracle.com/javase/7/docs/api/java/lang/Object.html?is-external=true#hashCode()" title="class or interface in java.lang">hashCode</a>, <a href="http://docs.oracle.com/javase/7/docs/api/java/lang/Object.html?is-external=true#notify()" title="class or interface in java.lang">notify</a>, <a href="http://docs.oracle.com/javase/7/docs/api/java/lang/Object.html?is-external=true#notifyAll()" title="class or interface in java.lang">notifyAll</a>, <a href="http://docs.oracle.com/javase/7/docs/api/java/lang/Object.html?is-external=true#toString()" title="class or interface in java.lang">toString</a>, <a href="http://docs.oracle.com/javase/7/docs/api/java/lang/Object.html?is-external=true#wait()" title="class or interface in java.lang">wait</a>, <a href="http://docs.oracle.com/javase/7/docs/api/java/lang/Object.html?is-external=true#wait(long)" title="class or interface in java.lang">wait</a>, <a href="http://docs.oracle.com/javase/7/docs/api/java/lang/Object.html?is-external=true#wait(long,%20int)" title="class or interface in java.lang">wait</a></code></li>
</ul>
</li>
</ul>
</li>
</ul>
</div>
<div class="details">
<ul class="blockList">
<li class="blockList">
<!-- ========= CONSTRUCTOR DETAIL ======== -->
<ul class="blockList">
<li class="blockList"><a name="constructor_detail">
<!--   -->
</a>
<h3>Constructor Detail</h3>
<a name="FirstOrderConverter(org.apache.commons.math3.ode.SecondOrderDifferentialEquations)">
<!--   -->
</a>
<ul class="blockListLast">
<li class="blockList">
<h4>FirstOrderConverter</h4>
<pre>public&nbsp;FirstOrderConverter(<a href="../../../../../org/apache/commons/math3/ode/SecondOrderDifferentialEquations.html" title="interface in org.apache.commons.math3.ode">SecondOrderDifferentialEquations</a>&nbsp;equations)</pre>
<div class="block">Simple constructor.
 Build a converter around a second order equations set.</div>
<dl><dt><span class="strong">Parameters:</span></dt><dd><code>equations</code> - second order equations set to convert</dd></dl>
</li>
</ul>
</li>
</ul>
<!-- ============ METHOD DETAIL ========== -->
<ul class="blockList">
<li class="blockList"><a name="method_detail">
<!--   -->
</a>
<h3>Method Detail</h3>
<a name="getDimension()">
<!--   -->
</a>
<ul class="blockList">
<li class="blockList">
<h4>getDimension</h4>
<pre>public&nbsp;int&nbsp;getDimension()</pre>
<div class="block">Get the dimension of the problem.
 <p>The dimension of the first order problem is twice the
 dimension of the underlying second order problem.</p></div>
<dl>
<dt><strong>Specified by:</strong></dt>
<dd><code><a href="../../../../../org/apache/commons/math3/ode/FirstOrderDifferentialEquations.html#getDimension()">getDimension</a></code>&nbsp;in interface&nbsp;<code><a href="../../../../../org/apache/commons/math3/ode/FirstOrderDifferentialEquations.html" title="interface in org.apache.commons.math3.ode">FirstOrderDifferentialEquations</a></code></dd>
<dt><span class="strong">Returns:</span></dt><dd>dimension of the problem</dd></dl>
</li>
</ul>
<a name="computeDerivatives(double, double[], double[])">
<!--   -->
</a>
<ul class="blockListLast">
<li class="blockList">
<h4>computeDerivatives</h4>
<pre>public&nbsp;void&nbsp;computeDerivatives(double&nbsp;t,
                      double[]&nbsp;y,
                      double[]&nbsp;yDot)</pre>
<div class="block">Get the current time derivative of the state vector.</div>
<dl>
<dt><strong>Specified by:</strong></dt>
<dd><code><a href="../../../../../org/apache/commons/math3/ode/FirstOrderDifferentialEquations.html#computeDerivatives(double,%20double[],%20double[])">computeDerivatives</a></code>&nbsp;in interface&nbsp;<code><a href="../../../../../org/apache/commons/math3/ode/FirstOrderDifferentialEquations.html" title="interface in org.apache.commons.math3.ode">FirstOrderDifferentialEquations</a></code></dd>
<dt><span class="strong">Parameters:</span></dt><dd><code>t</code> - current value of the independent <I>time</I> variable</dd><dd><code>y</code> - array containing the current value of the state vector</dd><dd><code>yDot</code> - placeholder array where to put the time derivative of the state vector</dd></dl>
</li>
</ul>
</li>
</ul>
</li>
</ul>
</div>
</div>
<!-- ========= END OF CLASS DATA ========= -->
<!-- ======= START OF BOTTOM NAVBAR ====== -->
<div class="bottomNav"><a name="navbar_bottom">
<!--   -->
</a><a href="#skip-navbar_bottom" title="Skip navigation links"></a><a name="navbar_bottom_firstrow">
<!--   -->
</a>
<ul class="navList" title="Navigation">
<li><a href="../../../../../overview-summary.html">Overview</a></li>
<li><a href="package-summary.html">Package</a></li>
<li class="navBarCell1Rev">Class</li>
<li><a href="class-use/FirstOrderConverter.html">Use</a></li>
<li><a href="package-tree.html">Tree</a></li>
<li><a href="../../../../../deprecated-list.html">Deprecated</a></li>
<li><a href="../../../../../index-all.html">Index</a></li>
<li><a href="../../../../../help-doc.html">Help</a></li>
</ul>
<div class="aboutLanguage"><em><script type="text/javascript" src="http://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS-MML_HTMLorMML"></script></em></div>
</div>
<div class="subNav">
<ul class="navList">
<li><a href="../../../../../org/apache/commons/math3/ode/FieldSecondaryEquations.html" title="interface in org.apache.commons.math3.ode"><span class="strong">Prev Class</span></a></li>
<li><a href="../../../../../org/apache/commons/math3/ode/FirstOrderDifferentialEquations.html" title="interface in org.apache.commons.math3.ode"><span class="strong">Next Class</span></a></li>
</ul>
<ul class="navList">
<li><a href="../../../../../index.html?org/apache/commons/math3/ode/FirstOrderConverter.html" target="_top">Frames</a></li>
<li><a href="FirstOrderConverter.html" target="_top">No Frames</a></li>
</ul>
<ul class="navList" id="allclasses_navbar_bottom">
<li><a href="../../../../../allclasses-noframe.html">All Classes</a></li>
</ul>
<div>
<script type="text/javascript"><!--
  allClassesLink = document.getElementById("allclasses_navbar_bottom");
  if(window==top) {
    allClassesLink.style.display = "block";
  }
  else {
    allClassesLink.style.display = "none";
  }
  //-->
</script>
</div>
<div>
<ul class="subNavList">
<li>Summary:&nbsp;</li>
<li>Nested&nbsp;|&nbsp;</li>
<li>Field&nbsp;|&nbsp;</li>
<li><a href="#constructor_summary">Constr</a>&nbsp;|&nbsp;</li>
<li><a href="#method_summary">Method</a></li>
</ul>
<ul class="subNavList">
<li>Detail:&nbsp;</li>
<li>Field&nbsp;|&nbsp;</li>
<li><a href="#constructor_detail">Constr</a>&nbsp;|&nbsp;</li>
<li><a href="#method_detail">Method</a></li>
</ul>
</div>
<a name="skip-navbar_bottom">
<!--   -->
</a></div>
<!-- ======== END OF BOTTOM NAVBAR ======= -->
<p class="legalCopy"><small>Copyright &#169; 2003&#x2013;2016 <a href="http://www.apache.org/">The Apache Software Foundation</a>. All rights reserved.</small></p>
</body>
</html>
